In a related touch screen device, it has been proposed to enable a user to operate respective display objects of operation targets with no mishit (mistouch) even if the display objects (e.g., image data containing symbols such as icons and buttons) are superposed or closely displayed on a screen thereof (see JP 2012-247861 A (hereinafter referred to as “Document 1”)).
In the touch screen device described in Document 1, the display objects are disposed in respective layers. The touch screen device is configured to switch between the layers according to the number of contact points obtained when the screen is touched by any of user's fingers, thereby enabling the operation of the display object of an operation target. For example, the touch screen device enables the user to operate the display object disposed in an upper-layer when the number of contact points by any of the fingers is one (when the screen is touched by one finger), and enables the user to operate the display object disposed in a lower-layer when the number of contact points by any of the fingers is two (when the screen is touched by two fingers).
The touch screen device described in Document 1 however requires a user to grasp the number of fingers associated with each of the layers in order to choose a layer in which the display object as the operation target is disposed. Therefore, what is needed is to facilitate user operation.